PSI - Issue 18

Ivica Čamagić et al. / Procedia Structural Integrity 18 (2019) 205 – 213 Author name / Structural Integrity Procedia 00 (2019) 000–000

209

5

on critical stress intensity factor values, for PM specimens is graphically represented in fig. 1, whereas its influence on critical crack length, a c , is shown in fig. 2, [15].

Table 5. Values of K Ic notched specimens in PM

Critical J-integral, J Ic , kJ/m 2

Critical crack length, a c , mm

Critical stress intensity factor, K Ic , MPa m 1/2

Specimen mark PM-1-1n PM-1-2n PM-1-3n PM-2-1n PM-2-2n PM-2-3n

Testing temperature,  C

60,1 63,9 58,6 43,2 44,7 45,3

117,8 121,4 116,3

38,5 40,8 37,5 40,0 41,4 41,9

20

87,2 88,7 89,2

540

Figure 1. Change in value of KIc , depending on the testing temperature for PM specimens Figure 2. Change in value of a c , depending on the testing temperature for PM specimens Calculated value of critical stress intensity factor, K Ic , and critical crack length, ac, are given in table 6, for specimens with the notch in the WM, tested at both room and elevated temperatures [15].

Table 6. Values of, K Ic notched specimens at WM

Critical J-integral, J Ic , kJ/m 2

Critical crack length, a c , mm

Specimen mark WM-1-1 WM-1-2 WM-1-3 WM-2-1 WM-2-2 WM-2-3

Testing temperature,  C

Critical stress intensity factor, K Ic , MPa m 1/2

72,8 74,3 71,1 50,2 52,6 48,4

129,6 130,9 128,1

20,2 20,7 19,8 17,4 18,2 16,8

20

93,9 96,2 92,2

540

F - δ and J -Δ a diagrams for the specimen with a notch in the WM are shown in fig. 3, for specimen denoted as WM 1-1, tested at room temperature, and in fig. 4, for specimen denoted as WM-2-1, tested at 540°C. The effect of test temperature on critical stress intensity factor values for specimens with the notch in the WM is shown graphically in fig. 5, whereas the effect of test temperature on critical crack length values, ac, is shown in fig. 6, [15]. Calculated value of critical stress intensity factor, K Ic , and critical crack length, ac, are given in table 7, for specimens with the notch in the HAZ, tested at both room and elevated temperatures [15].